The ruling by the Maine Supreme Judicial Court last week found that in offering an opt-out, the PUC did not adequately address safety concerns, and will have to revisit the issue. Thomas Welch, chairman of the Maine PUC, has already said his commission will re-examine possible health hazards associated to radio frequency waves, according to reports in The Forecaster.

“The commission is reviewing the order to determine what steps must be taken to comply with the court's decision. We have not reached a decision on what process will be required to do so. Any decision about process will be determined by commissioners in a public session," the PUC said in a statement.

Central Maine Power has installed most of the smart meters to its approximately 600,000 customers. The utility will be allowed to continue to install the rest of the meters while the PUC reviews safety issues. Regulators had initially found that CMP, which is owned by Iberdrola USA, had already adequately addressed those concerns.

Originally, the PUC cited data from federal and other state sources that have found that the RF radiation from digital smart meters does not pose safety concerns. However, Ed Friedman, who led the complaint against CMP, pointed specifically to a World Health Organization report from May 2011 that classified RF radiation as “possibly carcinogenic to humans.” That report, however, mostly discussed heavy cell-phone use, rather than the lower-level RF that most smart meters emit.

The WHO’s list of class 2B possible carcinogens includes hundreds of agents along with RF radiation, including coffee, fuel exhaust, some pickled vegetables and a laundry list of difficult-to-pronounce chemicals.

A study conducted by Maine’s Center for Disease Control and Prevention in 2010 did not find “any consistent or convincing evidence to support a concern for health effects related to the use of radiofrequency in the range of frequencies and power used by smart meters.”

About 8,000 customers have opted out of having a smart meter. For customers who want an analog meter, it’s $40 to have it installed and then $12 each month afterwards. For customers that want to keep the smart meter, but have the radio communications disabled, there is a $20 one-time fee and a monthly fee of $10.50.

Maine was first, but many other states have followed suit by offering some form of opt-out option for customers, usually with a fee attached. This recent ruling by the Maine court could give ammunition to other anti-smart meter groups that might ask for each state to do its own separate analysis of RF safety in meters.

Although the PUC will have to review safety concerns, the court did not agree with Friedman that smart meters trampled on constitutional rights. The commission has not announced how it will evaluate the safety of smart meters, or whether it can call on previous research or will have to commission a new study.